RESUMO
A markedly elevated BB isoenzyme fraction of serum creatine kinase was noted in four male siblings and correlated with typical radiographic findings of autosomal dominant osteopetrosis Type II (ADO Type II). Patients with other sclerosing bone diseases had no elevation of CK-BB. The precision of the electrophoretic mobility patterns and correlation by I-125 tagged radioimmunoassay method confirms that this is CK-BB. We postulate that the dysfunctional and/or immature osteoclasts in ADO are more dependent on CK-BB than on the usual tricarboxylic acid cycle for the production of energy. The correlation of marked elevation of serum CK-BB with radiographic evidence of ADO Type II may prove to be of value as a biologic marker in the early diagnosis of the illness and lead to better understanding of the metabolism of bone.